1. Field of the Invention
The invention relates to improvements in radiant heating systems of the type including a burner and an elongated heat radiating tube through which hot gases of combustion are passed.
2. Description of the Prior Art
Heating systems of the present type have been proposed in the past. One problem with such systems is that the high heat of the flame and initially the products of combustion can cause relatively rapid deterioration of the tube being heated. One technique for minimizing this problem is to pass a cylinder of air around the flame and early products of combustion to prevent contact thereof with the tube. This technique is illustrated in U.S. Pat. Nos. 3,399,833 (Sept. 3, 1968) and 4,044,751 (Aug. 30, 1977).
However, these patents each teach drawing of the exhaust gases through the tube by means of an exhaust fan provided at the outlet of the tube. A negative pressure is provided within the tube to prevent any leakage of fuel or products of combustion to the space being heated.
In accordance with the present invention, an effective cylindrical air stream is provided as desired by pressure in the tube created by means of a blower at the tube inlet. Two pressure checks are constantly made to ensure proper operation. Fuel is directly injected and burned within the tube, thus preventing any leaks at the tube inlet. A sealed compartment is also provided at the inlet. The one opening into the tube, other than at its inlet, is protected against leakage by means of a positive air pressure at that point.